HP OpenVMS Systems Documentation
OpenVMS System Manager's Manual
|Establishing a server management session||Section 25.3|
|Starting InfoServer Client for OpenVMS software automatically||Section 25.5.3|
|Making InfoServer devices available automatically||Section 25.6.3|
This chapter explains the following concepts:
|InfoServer functions||Section 25.1|
|LASTport protocols||Section 25.2|
|InfoServer Client for OpenVMS functions||Section 25.4|
|LASTCP utility functions||Section 25.5|
|LADCP utility functions||Section 25.6|
The InfoServer system is a high-performance virtual device server. It can make available, or serve, compact discs, read/write disks, magneto-optical (MO) devices, and tapes to client systems on the local area network (LAN). Systems running InfoServer Client software can connect to the virtual devices and use them as though they are locally attached devices.
Unlike a file server, the InfoServer system does not impose a file system on the virtual devices that it serves. For example, the InfoServer system can serve a disk with any type of on-disk file structure. The client system interprets the on-disk structure and uses its own native file system to access data. Multiple on-disk structures can be served by and accessed on a single InfoServer system at the same time.
The InfoServer system can perform the following functions:
Figure 25-1 shows the relationship of the InfoServer system to several possible client systems. In this figure, two compact discs and two hard disks connected to the server appear to the client systems as local devices. The VAX system and the RISC workstation might be using one or two of the compact discs for software distribution and online documentation, while the PC might be referencing a disk partition on the InfoServer system. The X terminal boots from the InfoServer system and uses InfoServer disks for page, font, and customization files.
Figure 25-1 InfoServer System Serving Clients
You can connect the InfoServer system to your Ethernet LAN and turn on the system. After the server is initialized, or bootstrapped, the server software automatically serves to client systems the device media connected to it. If you insert a compact disc into a server drive, the server detects this new device and automatically serves it to client systems by using the volume label as the service name.
The server bootstraps from its internal read/write device, on which the InfoServer software is preinstalled. InfoServer software updates are distributed on compact discs. As these new releases become available, you can install the software onto the internal device for subsequent booting. To update InfoServer software from the compact disc, follow these steps:
InfoServer> UPDATE SYSTEM DKn:
InfoServer> UPDATE SYSTEM DKn: FLASH
You can use the Software Products Library (formerly known as ConDIST) to update InfoServer software. After you log in to the InfoServer system, perform the following steps:
UPDATE SYSTEM DKn:
UPDATE SYSTEM DKn: FLASH
You might want to customize server features. You can control InfoServer
functions by logging in to the server and entering server commands,
described in detail in the InfoServer System Operations Guide.
25.1.1 Automatic Service Policies for Multiple Servers
The InfoServer system automatically serves its locally connected devices to clients when the server is first powered on or when a removable device (for example, a compact disc) is inserted into a drive. The server reads the volume label of each device and uses the label as the name of the service offered to clients.
You can disable the automatic service feature by using the InfoServer command SET SERVER AUTOMOUNT.
If multiple servers offer the same services, the client uses a rating scheme to select the appropriate service. Refer to the CREATE SERVICE command description in the InfoServer System Operations Guide for more information.
When you remove a compact disc from a server drive, the InfoServer
system ends all client connections to the associated service. The
InfoServer system also stops offering the associated service to client
25.1.2 High-Availability Feature to Reduce Service Interruptions
The InfoServer system provides a high-availability feature that is especially beneficial for OpenVMS clients. If the server ends a service connection for some reason (for example, the server reboots, or you remove a compact disc), the OpenVMS client enters mount verification for that volume. If the same service is offered by another InfoServer system on the LAN, the client automatically connects to that service.
For example, suppose you have two identical copies of the OpenVMS
Online Documentation compact disc in drives on two different servers.
If one server or drive fails, a new connection is established to the
duplicate disc on the other server. File operations continue as normal,
and users experience almost no service disruption.
25.1.3 Support for X Terminal Clients
X terminal clients use the InfoServer system to download their system software, provide font services, save configuration information, and page memory to and from InfoServer disks. For example, system files for Compaq's VXT 2000 windowing terminals can be installed from compact disc on the InfoServer system. Once installed, these files are downline loaded on demand to each terminal when it is powered on.
The terminals can dynamically allocate partitions on an InfoServer disk as needed. For example, when a user requests that terminal customizations be saved, the InfoServer system automatically creates a disk partition to hold the information and creates a network service name for that partition. Once customization information is saved, the user can recall the information at any time.
VXT 2000 terminals that are InfoServer clients can also be virtual memory machines. Such terminals can page sections of main memory to and from InfoServer disks as required. Because a VXT client has no local disk, it uses InfoServer disks as page disks. When main memory is paged out to disk, the VXT client requests the InfoServer system to create a partition. This partition is then automatically extended as needed. Partitions and their network service names are created dynamically, without requiring user action.
By default, the InfoServer disk DK1, which is the internal disk that
ships with each InfoServer 150 system, is enabled to allow VXT 2000
clients to allocate partitions remotely. Other disks can also be
enabled through the use of InfoServer commands.
25.2 Understanding LASTport Protocols
The InfoServer system uses the LASTport transport protocol and the LASTport/Disk and LASTport/Tape system application protocols to provide access to the virtual devices it serves to the LAN. These protocols provide high-performance access to disk and tape devices. The InfoServer system implements the server portion of the protocols, while the client systems that access InfoServer storage devices implement the client portion.
On OpenVMS systems running the LASTport transport, all Ethernet devices
must be terminated either by attaching the devices to an active network
or by using an appropriate terminator. Failure to terminate the devices
causes a system crash.
25.2.1 LASTport Transport Protocol
The LASTport protocol is a specialized LAN transport protocol that allows many clients to access InfoServer systems and perform reliable transactions. For the InfoServer system, a transaction is a device read or write operation. The LASTport protocol allows many client systems concurrently to read information from, and and write information to, an InfoServer storage device.
Unlike timer-based protocols, the LASTport protocol is a transaction-oriented protocol. Normally, information does not pass between a client and an InfoServer system unless the client initiates a transaction. The client system then runs a timer on the transaction, normally waiting from two to five seconds before assuming that the transaction is lost and retrying the operation.
The LASTport protocol does not provide any routing functions; it runs only in a LAN. The LASTport protocol type is 80--41. If the extended LAN uses any filtering devices, the devices must allow this protocol type to pass unfiltered so that clients can access InfoServer systems across the filtering device.
The InfoServer system uses a multicast address feature of the LASTport
protocol to establish connections to devices. The format of the
multicast address is 09--00--2B--04--nn--nn, where nn
depends on the work group enabled (refer to the InfoServer System
25.2.2 LASTport/Disk Protocol
The LASTport/Disk protocol is a specialized device protocol that uses the LASTport transport. That is, LASTport/Disk messages are delivered in LASTport messages. The LASTport/Disk protocol provides the mechanism for reading and writing logical blocks independent from any underlying file system. The clients that implement the LASTport/Disk protocol interpret the file system locally. By using the LASTport/Disk protocol for access to compact discs and read/write disks, the InfoServer system can support multiple client operating systems and on-disk structures concurrently.
The LASTport/Disk protocol also provides the naming facility to access
compact discs and read/write disks. The InfoServer system assigns each
virtual device a service name and allows clients to query the LAN for
these names. When the requested service is found, the client connects
to it, and device access can begin. When duplicate virtual devices are
available under identical service names, the protocol provides a
facility for load balancing among the available devices.
25.2.3 LASTport/Tape Protocol
Like the LASTport/Disk protocol, the LASTport/Tape protocol uses the LASTport transport. That is, LASTport/Tape messages are delivered in LASTport messages. The LASTport/Tape protocol provides the mechanism for reading and writing tape records. Tape devices attached to the InfoServer system appear to tape clients as locally attached devices.
The LASTport/Tape protocol also provides the naming facility to access
tapes. The InfoServer system assigns each tape device a service name
and allows clients to query the LAN for these names. When the requested
service is found, the client connects to it, and tape access can begin.
25.3 Establishing a Server Management Session
You can establish a server management session from a local or remote console terminal:
To make a remote connection to the InfoServer system for the first time, you must determine the server's default name. To do this, add the four-character prefix LAD_ to the hexadecimal Ethernet datalink address on the InfoServer system's cabinet. You can change this default name by using the InfoServer command SET SERVER NAME.
The server's name is the LAT service name to which you connect. For example, if the default server name is LAD_08002B15009F, you would enter the following command at the terminal server's prompt to manage the InfoServer system:
Local> CONNECT LAD_08002B15009F
Refer to your terminal server user's guide for information about the establishment of LAT service connections.
After you connect to the InfoServer system, you must enter an InfoServer password to establish the management session. The default server password is ESS. You can change the password with the InfoServer command SET SERVER PASSWORD.
The following example shows the establishment of a sample session using a DECserver 500 terminal server:
Local> CONNECT LAD_08002B133C1C Password: ESS (not echoed) Local -010- Session 1 to LAD_08002B133C1C established DEC InfoServer V3.1 InfoServer> SHOW SERVER
In this example, the terminal server's prompt is Local>, and a LAT session is established to the InfoServer system whose service name is LAD_08002B133C1C. The InfoServer system prompts for a server password. When you enter the correct password, the server prompts for InfoServer commands with the InfoServer> prompt.
At the end of the management session, you can enter the EXIT command at
the InfoServer> prompt. This command returns you to the terminal
server's Local> prompt if the management session is over a LAT
25.3.1 Server Management Commands
Table 25-1 summarizes InfoServer commands and their functions.
|BACKUP||Saves InfoServer-formatted disks.|
|BIND||Establishes a connection to the specified ODS-2 service and creates the virtual device VDK1 for that service.|
|CLEAR||Erases the console terminal screen.|
|COPY||Copies data from one disk or partition to another.|
|CRASH||Causes the server software to take a recognizable bugcheck, creating a dump if crashdump processing is enabled.|
|CREATE||Creates a new partition or service.|
|DELETE||Deletes a partition or service that was previously created.|
|DISCONNECT||Terminates a LASTport or LAT terminal server session.|
|ERASE||Erases the specified disk or partition; erases FUNCTIONS or SERVICES data from nonvolatile random-access memory (NVRAM).|
|EXIT||Terminates the management session.|
|HELP||Displays help text for the InfoServer commands.|
|INITIALIZE||Formats a read/write disk into an InfoServer disk.|
|LOOP||Automatically repeats any valid InfoServer command.|
Automatically repeats valid InfoServer commands every
3 seconds, clearing the screen and placing the cursor at the home position.
|PURGE||Purges old versions of VXT software.|
|REBOOT||Shuts down and reboots the server.|
|RECORD||Records data from an InfoServer disk or partition to a compact disc.|
|RESTORE||Resets the server to a previously saved system configuration.|
|RETRIEVE||Restores InfoServer-formatted disks saved by the BACKUP command.|
|REWIND||Rewinds an InfoServer tape.|
|SAVE||Saves configuration and service data for recovery after a server reboot.|
|SET||Sets partition, service, or server parameters.|
|SHOW||Displays the server's parameters and counters.|
|UNBIND||Deletes the VDK1 virtual device and terminates the connection to the remote service.|
|UNLOAD||Rewinds and unloads an InfoServer tape.|
|UPDATE||Installs one or more new software products or functions.|
|VERIFY||Validates the on-disk structure of a device formatted with the INITIALIZE command.|
|ZERO||Sets internal server counters to 0.|
The InfoServer system provides a Help facility that contains information about each server command, including parameters, qualifiers, and examples of its use. For detailed information about InfoServer commands, refer to the InfoServer System Operations Guide.